Hime Chen! Otogi Chikku Idol Lilpri S01E03 - The Princess is Forgetful! Pri!

Atsui Tarou is Ringo's teacher. Today he's already very intense from the beginning and suggests "Making something that will be the class's trademark for tomorrow's excursion!" However, none of the students pay attention to him. But he does not give up. His next suggestion is to stitch all of their handkerchiefs together to make a flag. However, all the students just leave their handkerchiefs and go home. After seeing that, Ringo, Leila, and Natsuki offer their help, but he insists that he has been "entrusted with their hearts" and begins to sew the handkerchiefs together. After a while, Leila goes back to the class room to pick something up she forgot. That's when she sees the flag Mr. Atsui has made; it's in tatters, about to fall apart on its own, so Leila decides to take it home to fix it, but…